This invention relates to the manufacture of glass bottles or other hollow glassware. The invention is concerned with the application of lubricant to the moulds in which parisons are made.
The manufacture of hollow glassware is a two stage process. First a "gob" of molten glass is dropped into a so-called "blank mould" where it is formed into a hollow parison. This is carried over into a "blow mould" where it is blown out into the bottle or other glass product. The blank moulds require periodic lubrication (so-called "swabbing"). It is notorious that it would be desirable to effect this lubrication automatically. There have been numerous proposals for this, for instance in U.S. Pat. Nos. 3,141,752, 3,480,422, 3,580,711, 3,623,856, 3,721,542, 3,814,594 and 4,391,620.
Nevertheless manual swabbing with a small mop remains widespread.
My U.S. Pat. 4,409,010, assigned to the assignees of this application, describes equipment for automatic spraying of blank moulds from fixed spray heads which spray while the moulds are open. This equipment has operated successfully in some plants.
We have, however, identified one difficulty with this equipment. This is difficulty in spraying the lower parts of a relatively deep mould, e.g. a blank mould used when the end product is a tall bottle.
This equipment, as shown in our EP-A-43261 sprays liquid lubricant mixed with air which is being supplied through closed ducts from a pressurised supply. Most of the earlier proposals also discharged liquid lubricant in air from a pressurised air supply. The only alternative appears to have been use of an airless lubricant spray, e.g. in U.S. Pat. Nos. 3,523,016 and 4,391,620.